How do I set one post to stay at top?

I put a slideshow in a post yesterday and would like it to stay at the top of my main page (recent posts). Is there a way to select (freeze, lock) one post to stay at the top of all other recent posts? Basically, I want to keep my slideshow posted just under my header and have all recent posts show up below it...

Being able to quickly and easily change the order of the posts is an important feature. I hope WordPress is aware of this. I'm really surprised that it's not already included in the software. Thanks for the helpful posts.